Dog the Bounty Hunter believes Brian Laundrie is alive, but not well.
The body of his fiancée Gabby Petito was found in Bridger-Teton National Park on Sunday (19 September), but his whereabouts are currently not known.
Reality TV star Dog - real name Duane Chapman - has joined the hunt for Laundrie and he reckons he's still alive.
Speaking to TMZ, the 68-year-old said: "I would assume he is alive. Not alive and doing well, but he's alive.
"There's no evidence of him being suicidal like that anywhere, and he didn't say that to anyone.
"And if you go to his Instagram pages and look at what kind of person he really is - and the books that he reads, and especially his very favourite books - that's not books for suicidal people."
Explaining why he thinks Laundrie has been hiding in the Florida Everglades, he said: "He's a survivalist, he's been on the Appalachian mountains for two months at a time by himself.
"Is he here right now? I'm not sure. Was he here a few days ago? Absolutely.
"But he could have got out during the night, and he would have to have help, I guess it might be from close to a family member and, you know, he's taken off somewhere else.
"I do not believe that he's in Mexico or Brazil. I've been to Mexico and if they know you're wanted and you're a Caucasian American, they're gonna turn you in for the reward."
Chapman went on to explain that he had turned over evidence to the FBI, which he hopes can be examined for DNA to prove that Laundrie had been hiding in Fort De Soto Park in Florida.
Previously, a survival expert said it's possible Laundrie could have been eaten in the Carlton Reserve - where police have been searching extensively.
Mark Burrow said it's possible that he has been eaten, with coyotes or bobcats likely to prey on him if he was injured or exhausted.
Meanwhile, if alligators got him, there could be nothing left to find.
Burrow told the Sarasota Herald-Tribune: "They like to put a carcass under a log, and let it get all rotten.
"Then the gator would eat you slowly."
But Burrow said it wouldn't be the gators which would be Laundrie's biggest concern.
He said: "If he's down there in the Carlton Reserve, he's living in hell.
"People have been making a big deal of the alligators and the snakes, but it's dehydration that's the real danger."
That's because, on top of all the dangerous animals in the preserve, there is also a scarcity of safe drinking water. Even if he was able to boil the water, Burrow said recent rains mean the water is full of tannins from foliage, which can be harmful to humans in high concentrations.
He added: "That can cause loose bowels. Not a good thing when you are already dehydrated."